Will my contacts still be there when I change the sim?

I have an iPhone 5 and I have to go overseas for a while. I need to change my sim from a regular sim card to an international sim card. When I do so, will my contacts still be on the hone or will I have lost everything?

The sim card doesn't store anything but tower data and service plan info everything else is internal storage. You shouldn't lose a single contact but if your worried enough about it just use an app to back your contacts up onto an SD card.